From: Ricardo Ribalda <ribalda@chromium.org>
Date: Fri, 20 Mar 2026 07:49:10 +0000 (+0000)
Subject: media: uvcvideo: Fix bug in error path of uvc_alloc_urb_buffers
X-Git-Tag: v7.0-rc6~31^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7c39f48568e0aec9bf6988cdbf833fdf8af19901;p=thirdparty%2Fkernel%2Flinux.git

media: uvcvideo: Fix bug in error path of uvc_alloc_urb_buffers

Recent cleanup introduced a bug in the error path of
uvc_alloc_urb_buffers(). If there is not enough memory for the
allocation the following error will be triggered:

[  739.196672] UBSAN: shift-out-of-bounds in mm/page_alloc.c:1403:22
[  739.196710] shift exponent 52 is too large for 32-bit type 'int'

Resulting in:
[  740.464422] BUG: unable to handle page fault for address: fffffac1c0800000

The reason for the bug is that usb_free_noncoherent is called with an
invalid size (0) instead of the actual size of the urb.

This patch takes care of that.

Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Closes: https://lore.kernel.org/linux-media/abycbXzYupZpGkvR@hyeyoo/T/#t
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Fixes: c824345288d1 ("media: uvcvideo: Pass allocation size directly to uvc_alloc_urb_buffer")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patch.msgid.link/20260320-uvc-urb-free-error-v1-1-b12cc3762a19@chromium.org
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
---

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 40c76c051da2..f6c8e3223796 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1751,7 +1751,8 @@ static void uvc_video_complete(struct urb *urb)
 /*
  * Free transfer buffers.
  */
-static void uvc_free_urb_buffers(struct uvc_streaming *stream)
+static void uvc_free_urb_buffers(struct uvc_streaming *stream,
+				 unsigned int size)
 {
 	struct usb_device *udev = stream->dev->udev;
 	struct uvc_urb *uvc_urb;
@@ -1760,7 +1761,7 @@ static void uvc_free_urb_buffers(struct uvc_streaming *stream)
 		if (!uvc_urb->buffer)
 			continue;
 
-		usb_free_noncoherent(udev, stream->urb_size, uvc_urb->buffer,
+		usb_free_noncoherent(udev, size, uvc_urb->buffer,
 				     uvc_stream_dir(stream), uvc_urb->sgt);
 		uvc_urb->buffer = NULL;
 		uvc_urb->sgt = NULL;
@@ -1820,7 +1821,7 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
 
 			if (!uvc_alloc_urb_buffer(stream, uvc_urb, urb_size,
 						  gfp_flags)) {
-				uvc_free_urb_buffers(stream);
+				uvc_free_urb_buffers(stream, urb_size);
 				break;
 			}
 
@@ -1868,7 +1869,7 @@ static void uvc_video_stop_transfer(struct uvc_streaming *stream,
 	}
 
 	if (free_buffers)
-		uvc_free_urb_buffers(stream);
+		uvc_free_urb_buffers(stream, stream->urb_size);
 }
 
 /*